Answer:
37.5 miles per hour
Step-by-step explanation:
The traffic along a stretch road moves at an average speed that carried inversely as the number of cars
Average speed= k/number of cars.
When there are 1,500 cars the average speed is 45
The first step is to calculate the constant k
45= k/1500
k = 1,500 × 45
k= 67,500
Therefore the average speed when there are 1,800 cars can be calculated as follows
Average speed= 67,500/1,800
= 37.5 miles per hour
Hence the average speed is 37.5 moles per hour
